Kessler

If you’ve seen Gravity, you’ll have noticed how a single piece of space debris can cause a cascade of destruction — the Kessler effect — that makes the entirety of space completely uninhabitable to spacecraft? Well, in the photo above, you can see the exit hole created by a tiny piece of aluminium space debris in a piece of Kevlar shielding — the same shielding that protects the manned modules of the International Space Station. Space debris is serious stuff.